Testing, Adjusting & Balancing (TAB) and HVAC Commissioning
NLS Contractors delivers testing, adjusting and balancing (TAB) and HVAC commissioning as a works package in Riyadh, Jeddah, Dammam and Khobar: airflow and water flow measurement, balancing to design values and functional testing, using NEBB or AABC procedures as specified and ASHRAE Guideline 0. Handover includes TAB reports, balancing sheets, functional test records and a commissioning report.
A system installed to the drawings will still not match them until it is balanced. Ducts and pipes are sized for design flows, but pressure drops on site differ from the calculation, valves sit at their factory settings, and the result is a cold room next to a hot one. Testing, adjusting and balancing, known as TAB, closes that gap.
TAB means measuring airflow at every terminal and diffuser, measuring water flow through coils, pumps and branches, and adjusting dampers, valves and fan or pump speeds until the readings meet the design values within the tolerance the specification gives. The procedure is NEBB or AABC, whichever the specification names, and the result is a signed report with the readings. The offer states who carries out the work.
Commissioning is wider. ASHRAE Guideline 0 describes the process: pre-functional checks that equipment is installed and started correctly, functional tests that systems do what the sequence of operations says, and a record of the results. A functional test runs a chiller through its stages, tests alarms and interlocks, and checks that pumps and AHUs respond to the controller.
Sequence testing needs the controls working. The DDC and BMS contractor must have points live and graphics ready before functional tests start, and the TAB work needs the controls to hold fans and valves at set positions. Programmes slip at this interface, so the offer shows the test sequence against the controls handover date.
Where the contract requires it, seasonal checks repeat key tests under a different load, for example peak summer cooling and then a milder period, to show the system works across its range. Price depends on the number of terminals, plant size, the number of systems and the commissioning scope. Lead time depends on scope and the offer states it. Send the HVAC drawings, the TAB and commissioning specification clause, the equipment schedule, the sequence of operations and the site city.
Specifications
- ✓Measurement: airflow at terminals, water flow at coils, pumps and branches
- ✓Balancing: adjusted to design values within the specification's tolerance
- ✓Procedures: NEBB or AABC as specified, ASHRAE Guideline 0 for commissioning
- ✓Functional testing of sequences with the DDC controls and BMS
- ✓Seasonal checks where the contract requires them
- ✓Handover: TAB reports, balancing sheets, functional test records, commissioning report
Frequently Asked Questions
Who carries out TAB and which procedure applies?+
The specification names the procedure, NEBB or AABC. The offer states who carries out the work, and the consultant can witness the readings.
When can TAB start on site?+
After installation is complete, the systems are cleaned and flushed, equipment is started, and the controls can hold dampers and valves in position. Starting earlier means measuring a system that will still change.
What is the difference between TAB and commissioning?+
TAB sets flows to the design values. Commissioning tests that the whole system, controls and alarms included, works as the sequence of operations says, and records it.
What does a TAB report contain?+
Design and measured airflow and water flow at each terminal and branch, fan and pump readings, the instruments used, and the final settings. It is signed and goes into the handover file.
Who supplies Testing, Adjusting & Balancing (TAB) and HVAC Commissioning in Saudi Arabia?+
NLS Contractors (Northlane Solutions Company) supplies Testing, Adjusting & Balancing (TAB) and HVAC Commissioning across Saudi Arabia, including Riyadh, Jeddah, Dammam and Jubail. Send your specification and quantities to info@nlscontractors.com or info@northlanesolution.com for a quotation.